In the conventional art, a known memory system would be such that includes memory devices arranged in a matrix on intersections of plural word lines extending in a row direction and plural data lines extending in a column direction. With such memory systems a known technique used would be such in which redundant columns are previously integrated in the memory system, that always a redundant column to be selected instead of a bad column.
The conventional technique usually requires a circuit (e.g., multiplexer) for outputting a predetermined number of data while replacing the bad columns. However, there is a problem in that when the number of data to be outputted is large, wiring becomes complicated while a circuit scale becomes larger.